Modern flight deck displays for vehicles (such as aircraft or spacecraft) display a considerable amount of information, such as vehicle position, speed, altitude, attitude, navigation, target, and terrain information. In the case of an aircraft, most modern displays additionally display a flight plan from different views, either a lateral view, a vertical view, or a perspective view, which can be displayed individually or simultaneously on the same display.
The lateral view, generally known as a lateral map display, is basically a top-view of the flight plan, and may include, for example, a top-view aircraft symbol, waypoint symbols, line segments that interconnect the waypoint symbols, and range rings. The lateral map may also include various map features including, for example, weather information, terrain information, political boundaries, and navigation aids. The terrain information may include situational awareness (SA) terrain, as well as terrain cautions and warnings which, among other things, may indicate terrain that may obstruct the current flight path of the aircraft. The perspective view provides a three-dimensional view of the vehicle flight plan and may include one or more of the above-mentioned features that are displayed on the lateral map, including the terrain information. In this regard, some modern flight deck display systems incorporate a synthetic terrain display, which generally represents a virtual or computer simulated view of terrain rendered in a conformal manner.
A flight deck display system may cooperate with a terrain avoidance and warning system (TAWS) that generates alerts when the aircraft is proximate to or is approaching terrain that might represent a potential flight path conflict. Traditional TAWS alerts include audible messages (such as a computer generated or recorded voice that says “TERRAIN AHEAD” or “PULL UP”) and/or visual notifications (such as a popup graphic that appears on the lateral view or the perspective view). For example, FIG. 1 is a schematic representation of a conventional lateral map display 10 that includes a top view of terrain 12, an aircraft symbol 14, and a range circle 16 that indicates a range of ten miles surrounding the aircraft. Lateral map display 10 depicts a condition where the current flight path of the aircraft might conflict with some approaching terrain. Consequently, the TAWS generates an alert or command that causes the flight deck display system to render a graphical message 18 on lateral map display 10. Some flight deck display systems also graphically highlight potentially conflicting terrain that corresponds to a TAWS alert. For example, non-conflicting terrain that is relatively far from the current flight path could be rendered in a green color, while potentially conflicting terrain could be rendered in a red or amber color. In FIG. 1, for example, potentially conflicting terrain 20 has been rendered in manner that contrasts with the remainder of the terrain.